Blood pressure in hemodialysis: targets?

Abstract

Purpose of review: In the absence of 'hard' clinical-trial evidence to define optimal blood pressure (BP) targets and validate different BP measurement techniques, management of hypertension in hemodialysis is based on expert opinions. In this review, we provide a comparative evaluation of out-of-dialysis BP monitoring versus dialysis-unit BP recordings in diagnosing hypertension, guiding its management and prognosticating mortality risk.

Recent findings: Owing to their high variability and poor reproducibility, predialysis and postdialysis BP recordings provide inaccurate reflection of the actual BP load outside of dialysis. Contrary to the reverse association of peridialytic BP with mortality, elevated home and ambulatory BP provides a direct mortality signal. Out-of-dialysis BP monitoring, even when done in the clinic, is a reliable approach to manage hypertension in the dialysis unit. Whenever none of these measures are available, median intradialytic SBP can provide a better estimate of interdialytic BP levels compared with peridialytic BP measurements.

Summary: Although out-of-dialysis BP monitoring have better diagnostic accuracy and prognostic validity, randomized trials are needed to ascertain BP targets for managing hypertension in hemodialysis patients.

Figure 1:. Prognostic association of dialysis-unit and interdialytic BP with mortality among patients on hemodialysis.

Hazard ratios for all-cause mortality for quartiles of systolic BP. Both home BP and ambulatory BP were prognostically informative. Conversely, dialysis-unit BP recordings did not achieve statistical significance in terms of prognostic value. Home systolic BP ranging from 125 to 145 mmHg or 44-hour ambulatory systolic BP ranging from 115 to 125 mmHg appear to carry the lowest risk for all-cause mortality. (Reprinted with permission from Alborzi et al. Home blood pressures are of greater prognostic value than hemodialysis unit recordings. Clin J Am Soc Nephrol 2007; 2:1228–34)